1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Trying to find mass given force, distance, and time.

  1. Feb 4, 2012 #1
    1. The problem statement, all variables and given/known data

    A dockworker applies a constant horizontal force of 70.0 N to a block of ice on a smooth horizontal floor. The frictional force is negligible. The block starts from rest and moves a distance 11.0 m in a time 4.80 s

    2. Relevant equations
    A)What is the mass of the block of ice?
    B)If the worker stops pushing at the end of 4.80 s, how far does the block move in the next 4.20 s?

    3. The attempt at a solution
    A)F=m*a, 70.0=x*11.0/4.80
    70.0/(11.0/4.80)=x, x=30.5 which was wrong.
    B)I have absolutely no idea where to start or what to do on this part.
  2. jcsd
  3. Feb 4, 2012 #2


    User Avatar
    Science Advisor
    Homework Helper

    welcome to pf!

    hi jad6016! welcome to pf! :wink:
    no, you've used a = distance/time, which is wrong …

    use one of the standard constant acceleration equations to find a :smile:
  4. Feb 7, 2012 #3
    find first the acceleration
    derive the d=vit+1^2at^2
    that's what i think
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook